a) Field of the Invention
The present invention concerns a system for regulating the flow of water in a conventional, residential toilet. In this application, a residential toilet ,is one in which a first valve controls the flow of water into a toilet tank and a second valve controls the flow of water from the toilet tank into a toilet bowl. On the other hand, a commercial toilet does not have a toilet tank and a single valve controls the flow of water directly into the toilet bowl.
b) Description of Related Art
Referring to FIG. 1, a conventional, residential toilet 10 includes a first valve 12 regulating water flow into a toilet tank 14 from a water supply 16. First valve 12 is controlled by a float 18 such that as the water rises to a predetermined level 20 in toilet tank 14, the buoyancy of float 18 causes first valve 12 to close, thereby inhibiting further water flow into toilet tank 14.
A second valve 22 is interposed between toilet tank 14 and a toilet bowl 24 to regulate water flow therebetween. Specifically, a "flapper" valve 22 is operated by a handle 26 via a pull chain 28. Between uses, water level 20 is maintained in toilet tank 14 by virtue of a valve face 30 sealingly abutting a valve seat 32. Actuation of handle 26 (in the direction indicated with arrow "A") causes pull chain 28 to lift valve face 30 away from valve seat 32, whereupon water in toilet tank 14 is passed through flapper valve 22 into toilet bowl 24. Flapper valve 22 is made to be buoyant so that the rush of flowing water from toilet tank 14 into toilet bowl 24 does not re-close flapper valve 22 (FIG. 1 shows the conventional, residential toilet in this state). As toilet tank 14 is drained, the buoyant force on flapper valve 22 is lost and valve face 30 re-engages valve seat 32, thereby re-closing flapper valve 22. Concurrent with draining toilet tank 14, float 18 drops below water level 20, whereupon valve 12 connects water supply 16 to toilet tank 14. Refilling toilet tank 14 commences when valve face 30 re-engages valve seat 32, and terminates when float 18 is buoyantly forced up to water level 20.
For proper operation, when the flapper valve 22 is closed, it is important that the pressure differential on the opposite sides of the flapper valve 22 overcome its buoyancy. That is to say, the combined force of the static pressure caused by the water in the toilet tank 14 on top of the flapper valve 22, plus the vacuum caused by the void underneath the flapper valve 22, exceeds the buoyant force of the flapper valve 22. This ensures the flapper valve remains closed between uses. Separating the valve face 30 from the valve seat 32 substantially reduces the pressure differential such that the buoyant force of the flapper valve 22 becomes superior to the force caused by the pressure differential. Consequently, the flapper valve 22 remains open from the time handle 26 is actuated, until toilet tank 14 is substantially drained. Further, flapper valve 22 must be sized to pass more water than water supply 16 can simultaneously provide. This ensures water supply 16 cannot maintain flapper valve 22 open indefinitely.
This known arrangement dispenses a single, predetermined water flow volume (based on the water level in a toilet tank of a given volume) without requiring the operator to modulate the duration or sequence for operating the valves. There is no mechanism which enables the user to select between a lower water flow volume, e.g. three gallons for liquid or light wastes, and a higher water flow volume, e.g. five gallons for solid wastes. Additionally, although it may be possible to forcibly alter the relationship between float 18 and the first valve 12 to adjust toilet tank water level 20, there is no provision in a conventional, residential toilet for adjusting toilet bowl water level 34.